Weights and Weightways.Pdf

Reprinted from the U. S. Lighthouse Society’s The Keeper’s Log – Winter, 2016 <www.USLHS.org> Weights and Weightways at American Lighthouses By John T. Graham Crooked River Lighthouse. USLHS archive photo. It had been a long January 1927 night, and Keeper Thorwald Hansen at the Crooked River, Florida, Lighthouse was tired. His assistant was ill and so the nightly watch fell to him alone. The fourth-order Fresnel lens was rotated every 12.5 seconds by a clockwork driven by the 150 pounds of iron weights that hung on the end of a cable. Keeper Hansen had let these weights descend almost to the bottom of the tower, which took about 12 hours, so now he would have to wind them 80 feet back to the top before the lens came to a halt. 34 Clockworks—Winter 2016 Reprinted from the U. S. Lighthouse Society’s The Keeper’s Log – Winter, 2016 <www.USLHS.org> he bright light that beamed from the “winding of the weights,” just as it put an the tower of a lighthouse, whether end to the nightly lighting of the lamp. it was a tall one near the shore or a Today just a handful of lighthouses still short one high on a headland, was have a Fresnel lens that rotates by use of a a welcoming, comforting, and nec- weighted clockwork; many others still display essary beacon to the mariner navigating the remnants of such a system, some with the often treacherous waters of the coastal United weights rusting away in the weightway; but in States. The single most important service that the vast majority of cases, the weights them- a lighthouse provided to that mariner was to selves disappeared long ago when the electric confirm that “You are here” along those oth- motor relegated them to the junk pile. The erwise dark and foreboding shores. following lighthouses still have an operational It was not enough for that light to be only lens that is rotated by a weight-driven clock- bright, as the ship master would then still be work: Split Rock, Minnesota; Point Reyes, wondering which lighthouse he was viewing. California; Elbow Reef, Abaco, Bahamas (the This was especially true where the lights from Elbow Reef light still uses a kerosene lamp, several different lighthouses could be seen from perhaps the last in the world to do so); Dixon a given location. Thus, from the earliest dates, Hill, San Salvador, Bahamas; La Martre, Que- lighthouse administrators sought to make the bec. There may, of course, be others. light from each tower somehow unique. Each In the typical system, it was a “rope” light was to have its own “signature” or “char- (in earlier days made of fiber, in later days acteristic” that set it apart from its neighbors. Weight at Pigeon Point, California. Photo by made of iron/steel) that was wound onto the With the advent of the use of the highly ef- Thomas Tag. drum of the clockwork. This rope held the ficient Fresnel lenses in the lantern rooms, one weights. The amount of weight needed was of the most common methods of achieving In the days before electricity and electric mo- determined by the weight of the lens to be this was to make some lenses appear to flash. tors came to the shores, it was a weight-driven turned, the speed at which it needed to ro- The technical differences between lenses gearbox that provided the motive power to turn tate to produce the specific characteristic as- that exhibited a flashing characteristic and even immensely heavy Fresnel lenses to produce signed to that light, and the gearing ratios of those that did not are explained well by many those flashes. For a technical look at these sys- the clockwork itself. This all went into deter- others in many other sources. For my pur- tems, refer to “The Clock Without Hands” by mining how fast the weights would descend. poses here, suffice it to say that most lenses Thomas Tag, which can be found in the Spring Lighthouse engineers then had to determine that exhibited a light that appeared to flash 2008 issue of this journal. Another great source how far down the tower they could or should had to turn, or rotate. It was the passing of is the U.S. Lighthouse Society’s website, specifi- descend and at what point the keeper on each of the “bull’s eye” sections of the lens cally www.uslhs.org/clockworks. Information duty needed to wind them up again. between the lamp in the epicenter and the on the various types of clockworks and their Although this article focuses on the eye of the viewer, however far away he might operation can be found in these and many oth- weight systems used in the Fresnel lens era, be, that created the appearance of the flash. er sources. This article will focus on the weights lamp assemblies used before the advent of that drove the gears those revolutionary lenses often were rotat- and the paths they ed as well, using a similar, if simpler, system traveled from top to to attempt to produce a distinctive charac- bottom of the light teristic for particular lights. towers. The earlier lighthouses utilized wick lamps Keeper Han- with a reflector to direct more of the light sen, noted in the forward. There were often several to many introductory para- of these lamps in a given lighthouse, usually graph, was simply mounted in a “chandelier” arrangement. Ma- performing one of jor seacoast lights might have had 20 or more the many normal individual lamps in the arrangement, which tasks of a light- were arranged so that the chandelier was two- keeper, tasks that sided, three-sided, or even four-sided. To the had not changed mariner, these lights would show an “occult- for decades. The ing” pattern of light followed by lesser light arrival of electricity and/or darkness, the interval being deter- to the remote sites mined by the arrangement of the lamps. where most light- Little is known about the weights or Weights visible in drop tube window, originally an access door. Split houses are located weightways in the early towers, but as the Ar- Rock, Minnesota. Photo by the author. brought an end to gand-type lamps used in those days weighed The Keeper’s Log—Winter 2016 35 Reprinted from the U. S. Lighthouse Society’s The Keeper’s Log – Winter, 2016 <www.USLHS.org> Much of the informa- Any blank space indicates that the inspect- tion for this article was ob- ing officer did not complete that section of tained directly from staff the report. For my purposes here, I was most at the various lighthouses interested in the following categories: how noted. Unfortunately, much weight was used and how frequently since it has been decades the weights were wound. since a clockwork system How Much Weight Was was used at most lighthouses, information about Used? them is simply unknown t was my naïve expectation that larger or not remembered. Ilenses would have required more weight, The other sources of but this was clearly not the case. Seventy-five information used are of the inspection reports reviewed noted the actual lighthouse inspec- amount of weight in use. These ranged from tion reports from the a low of 30 pounds for a third-order lens National Archives, as at Ameila Island, Florida, to a high of 503 Centered drop tube, Split Rock, Minnesota. Photo by Lee Radzak. compiled into a database pounds for a second-order lens at Kilauea by volunteers of the U.S. Point, Hawaii. Twenty-two of the reports relatively little compared to even the smaller Lighthouse Society. Although hundreds noted weights of 200 pounds or more. order Fresnel lenses, correspondingly less have thus far been transcribed, hundreds Although the radius of any given Fresnel weight would have been required. When the more remain to be so transcribed. Although lens is the measure of its “order,” other dimen- first use of a clockwork to rotate a chandelier of there is great inconsistency in the work of sions, and thus the total weight, can vary sig- lamps was put into use will be left to other his- the various inspectors over the years, these nificantly in lenses of the same order. Another torians. Most likely the weights simply hung reports comprise an invaluable glimpse factor is the rotational system in use. Some down from the clockwork, but a reference to into lighthouse operation. [USLHS.org; lenses used a chariot wheel system; some ro- an actual weightway is found in the archives Resources; Lighthouse Databases; then En- tated on a ball-bearing plate; still others turned of the Cape San Blas, Florida, Lighthouse. ter the National Archives Database.] Data on a bed of mercury. There are likely other In an 1848 letter to the district supervisor at from these reports is shown on page 38. variables of which I am not aware. Apalachicola, Light-House Establishment Su- The following is a summary of the in- perintendent Stephen Pleasonton requested dividual weight amounts noted for various that the plans for the staircase and lantern deck orders of lenses: for the lighthouse then under design for this Hyper-radial lens: location be modified to allow for “clockwork Makapuu, Hawaii, 121 pounds and weights.” Such systems had undoubtedly First-order lens: already been in use for decades if not longer. low at Pensacola, Florida, 80 pounds; What did the weights look like? There is high at Cape Fear North Carolina, no single answer to this question; as in al- 500 pounds most all aspects of lighthouse design, there is Second-order lens: a tremendous variety.

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